Automatic slack adjuster for brakes



A. R. K. DUURSON. AuroMAnc SLAcK Amus'ren Fon BRAKES.

FILED Aus. I8. |921.

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Patented Een. 26, i922.

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EL RUDOLF KONRAD DJURSON, OF MALMO, SWEDEN.

AUTOMATIC SLACK ADJ FOR BRAKES.

Application mea .August is, 1,921. serial No@ 493,369.

a feedingdevice is arranged in the brake mechanism, which feeding device acts upon a turnbuckle or other suitable take-up device for reducing th'e'pl'ay, the feeding device bein connectedwith a yielding meinber Whic when friction arising in the mechanism by the increasing brake pressure stops further movement of the same,

absorbs the rest or the movement of'. the feeding device during the braking opera-- tion. Devices of this kind are alreadv known.

The object of the present invention is to eliminate the following inconveniences encountered in the use o1c slack adjusters oi' this type.` It is diiiicult to bring about a simple uncoupling when the apparatus is going to be loosened by hand, for instance for the purpose of inserting new brake shoes and besides it is impossible to avoid that a subsequent take-up of the play is effected under certain circumstances at the loosening of the brake on account of the torsional springs hitherto used then being under tension.

The linvention is illustrated in the accompanying drawing in which Fig. 1 1s a side y view ofv the slack adjuster device and Fig.

2, is a longitudinal section of the new arrangement on a larger scale. Fig. 3 is a cross section and Fig. 4 shows a part of the device.

The brake cylinder is indicated by the numeral 1 and the brake levers 5, 6 are in the usual manner connected with the brake cylinder and the piston rod and they are also connected'with each other by means of the rod 2, 3 carrying the slack adjuster proper. The ends of the brake levers are in a known way connected with the brake pull rods 8, 9 leading to the brake shoes. On the outer end of the piston rod or on any other suitable part of the brake mechanism a roller 11 is provided running in a slot or the like l2 in a bar link 13. Another roller 14 mounted on the end of the bar 15 is also made to slide in the same slot, said latterroller at its other end being connected with a member acting directly upon the slack adjuster by means of a lever y4 pivote'd in the brake lever 6. The piston rod and the end of the connecting .rod 15 guided inthe slot 12 are pivotally connected with c each other by means of a link or the like 17. The bar link 13 is connected with some part of the frame of the ycar by means of.

a bar18 and a pin 19 in sucha `Way that it will be prevented from mo-ving inthe longitudinal direction but not from participating in the lateral movements of the piston rod. l n

The slot 12 has an oblique portion 20 arranged in such a manner in relation to the crank 31 on theslack adjuster that when the roller14 on the end of the connecting rod 15 passes through the same at the motion ofthe brake piston the slack adjuster will :be actedfupon for taking up of an eX- cess play. Insteado using springs as yielding members the following steps are taken according to the present invention: On the pipe `16 fixed to the take-up nut of the slack adjuster an annular ilange 21 is provided carrying a friction-disc 22 which is made to turn around said yflange and provided with ratchet teeth 23 at its circumference. A plate 24 is provided at each side of the disc 22 said plates 24 being pressed against the sides of the disc 22 by means of a suit` able number of pressure springs 25 mounted on pins 26 extending through holes in the flange 21 and in the plates 24. A pawl 27 engages the teeth 23, saidy pawl beingl mounted in a housing 28 enclosing the parts `mentioned above and provided with a projecting pin 29. 0n this pin a 'sleeve or the like 30 is mounted said sleeve being connected with a crank 31 pivotally connected with the lever 4.

rllhe pawl 27, which is preferably acted upon by a spring', is connected with a disengaging mechanism 32 accessible from outside by means of which it can be brought out of engagement with the disc 22 when the apparatus is to be turned backwards byy hand.

The pipe 16 is at its outer end mounted on a stud 33 screwed into the bottom of acavity in the end of the rod 2, and on its very end said pipe carries a flange or ring 34 kept in its place in the cavity by means of a nut 35 screwed into the latter.

The housing 28 is placed between the end of the nut or sleeve and astrapy 36k fas'- tened on the pipe 16.

Having nowy described my invention what I claim is f 1. An automatic slack adjuster, including a threaded element, a feeding device acting upon the threaded element for adjusting the slack in a brake mechanism, a yielding member connected with the feeding device for taking up excess movement of the feeding device, said yielding member including a friction mechanism, and a, manually controlled ratchet device cooperating therewith, whereby kthe taking up of the slack may be prevented at Will. l

2. Automatic slack adjuster consisting of a threaded element, a feeding device acting upon the threaded element for adjusting the slack in a brake mechanism, a yielding member connected with the feeding device for taking up theexcess movement of the feeding mechanismy said yielding member consisting of a friction-disc arranged between two plates fastened on the threaded element said friction-disc being provided with teeth on its circumference in which a pawl connected with the feeding device engages.

Automatic slack adjuster consisting of a threaded element, a feeding device acting upon the threaded element for adjusting the slack in a brake mechanism, a. yielding member connected with the feeding device for taking up the excess movement of the feeding mechanisml said yielding member consisting of a friction-disc arranged between two plates fastened on the threaded element and made to slide along but not to turn around the threaded member said plates being pressed against-the sides of the friction-disc by means of springs.

Automatic slack 'adjuster consisting of a threaded element, a feeding` device acting upon the threaded element for adjusting the slack in a brake mechanism, a yielding member connected vwith the feeding device for taking up the excess movement of the feeding mechanism said yielding member con sisting-of a friction-disc arranged between two plates fastened on the threaded element said lfriction-disc being provided with teeth on,y its circumference, a pawl connected with thev'feeding device to engage the teeth of saidfr'iction-disc, the vpawl being acted upon by a spring and pivoted in a housing enclosing the frictionflisc and the plates and carrying a pin connected with the feeding device.

ln testimony whereof, l have signed my name to this speciizcation in the presence of two subscribing witnesses.

AXEL RUDOLF KONRD'DJURSN;

lVitnesses:

GEORGE J. F. CAREY, ARTHUR BILLGERT.' 

